In Japan, it's known as masking tape (マスキングテープ). The term "washi tape" refers to the fact that the tapes are made from Japanese rice paper and differentiates it from typical masking tape you might find in the hardware store. Washi tape is reusable, biodegradable, tree free and made out of highly renewable resources. Just like masking tape it does come off and does not leave a sticky mess. Furthermore, it is beautiful and useful, you can tear it, stick it, reposition it and even write on it! Great for DIY projects, scrapbooking, you name it!